London Phoenix

A stupid question: FMB tubular tyres come with a little rubber O-ring around the valve stem. What am I supposed to do with that?

I assume I take it off before glueing and then, with the tyre fitted, slip it down to the bottom of the protruding valve, to limit water entering from the the top of the rim?

Thanks, Max

It’ll help stop any valve rattle if you decide to put it back on. Or bin it and use some electrical tape like the pros do

Cheers Nick. I think I can leave it off. Everything rattles in cross, it's not the valve that will bother me!